Invasive drug administration can be a difficult procedure to alter, once it is initiated. The dynamic nature of drug administration can be difficult to anticipate. Feedback mechanisms can be used to monitor drug administration and exert control mechanisms on the system.
As drugs are becoming more sophisticated and endogenous compounds continue to be discovered and synthesized, mechanisms to deliver drugs in a more exact and versatile fashion will allow for fuller drug utility to be realized.
Drugs have been released at the tip of solid catheters by applying laser energy as an aid in tumor or local drug therapy. Compounds have been encapsulated with the anticipation of releasing them in a controlled way for many years in the form of timed release capsules, matrix embedded tablets, or controlled release granules. A catheter product exists whereby an interior coating of antibiotic provides prophylactic protection against infection by providing zero order release of drug from the interior surface.
Standard drug infusion consists of employing infusate of constant concentration with respect to an active compound. The volumetric flow rate determines the rate at which a drug or compound is delivered to the systemic circulation or organ system. Altering the rate of drug delivery necessitates altering the volumetric flow rate of the infusate apparatus. Various catheter designs and drug delivery systems are described in U.S. Pat. Nos. 5,304,121; 5,482,719; 6,086,558; 5,991,650; 5,795,581; 5,470,307, 5,830,539; 5,588,962; 5,947,977; 5,938,595; 5,788,678; 5,868,620; 5,843,789; 5,797,887; 5,773,308; 5,749,915; 5,767,288; and 5,665,077.
The present invention overcomes the shortcomings of previous designs and systems in a novel and unobvious way.